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III.B.3.b. (XIII.C.2.)

Vibrational frequency scaling factors

Calculated vibrational frequencies ("theory" in table) are calculated at ROHF/6-311G*
Scale factor How many Source
Molecules Vibrations
0.856 ± 0.159 36 57 cccbdb
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Formula Name Mode Symmetry Frequency Count
Theory Experiment ratio molecules vibrations
CF3 Trifluoromethyl radical 1 A1 1214 1089 0.897 1 1
    2 A1 766 701 0.915 1 2
    3 E 1421 1260 0.887 1 3
    4 E 561 509 0.906 1 4
HCO Formyl radical 1 A' 2970 2434 0.820 2 5
    2 A' 2147 1868 0.870 2 6
    3 A' 1269 1081 0.852 2 7
C3H3 Propargyl radical 1 A1 3632 3322 0.915 3 8
    6 B1 737 687 0.932 3 9
    7 B1 472 490 1.038 3 10
HO2 Hydroperoxy radical 1 A' 4090 3436 0.840 4 11
    2 A' 1659 1392 0.839 4 12
    3 A' 1269 1098 0.865 4 13
CH Methylidyne 1 Σ 3065 2861 0.933 5 14
OH Hydroxyl radical 1 Σ 4054 3738 0.922 6 15
NF2 Difluoroamino radical 1 A1 1276 1075 0.843 7 16
    2 A1 673 573 0.852 7 17
    3 B2 1189 942 0.793 7 18
CF Fluoromethylidyne 1 Σ 1403 1308 0.932 8 19
CCl carbon monochloride 1 Σ 863 877 1.016 9 20
SiF silicon monofluoride 1 Σ 886 857 0.968 10 21
SiN Silicon nitride 1 Σ 1326 1151 0.869 11 22
LiO lithium oxide 1 Σ 868 815 0.938 12 23
BS boron sulfide 1 Σ 1263 1180 0.934 13 24
AlS Aluminum sulfide 1 Σ 683 617 0.903 14 25
CP Carbon monophosphide 1 Σ 1461 1240 0.849 15 26
NaO sodium monoxide 1 Σ 524 492 0.939 16 27
BeF Beryllium monofluoride 1 Σ 1273 1247 0.980 17 28
PH2 Phosphino radical 1 A1 2529 2310 0.913 18 29
    2 A1 1254 1102 0.879 18 30
SiH3 Silyl radical 1 A1 2329 2136 0.917 19 31
    2 A1 897 728 0.812 19 32
    3 E 2340 2185 0.934 19 33
    4 E 1017 922 0.907 19 34
NH2 Amino radical 1 A1 3636 3219 0.885 20 35
    2 A1 1718 1497 0.872 20 36
    3 B2 3722 3301 0.887 20 37
NH Imidogen 1 Σ 3571 3283 0.919 21 38
SiH Silylidyne 1 Σ 2138 2043 0.955 22 39
BeCl beryllium chloride 1 Σ 844 847 1.003 23 40
SH Mercapto radical 1 Σ 2810 2696 0.959 24 41
SiCl Clorosilylidyne 1 Σ 517 536 1.037 25 42
PH phosphorus monohydride 1 Σ 2498 2364 0.946 26 43
MgH magnesium monohydride 1 Σ 1580 1493 0.945 27 44
BH2 boron dihydride 2 A1 1125 954 0.848 28 45
AlH2 aluminum dihydride 1 A1 1975 1770 0.896 29 46
    2 A1 823 760 0.924 29 47
    3 B2 1986 1807 0.910 29 48
MgF Magnesium monofluoride 1 Σ 743 712 0.958 30 49
MgCl magnesium monochloride 1 Σ 456 462 1.013 31 50
ClO Monochlorine monoxide 1 Σ 841 854 1.015 32 51
PF phosphorus monofluoride 1 Σ 869 847 0.974 33 52
BeOH beryllium hydroxide 2 A' 1319 1246 0.944 34 53
S2 Sulfur diatomic 1 Σg 801 726 0.906 35 54
ClS2 Sulfur chloride 1 A' 567 662 1.168 36 55
    2 A' 519 450 0.866 36 56
    3 A' 239 196 0.822 36 57

How do we calculate the scaling factor?


Histogram of vibrational frequency ratios

Ratios greater than 1.35 are in the 1.35 bin. Ratios less than 0.7 are in the 0.7 bin.

20
15
10
5
0
0.70 0.75 0.80 0.85 0.90 0.95 1.00 1.05 1.10 1.15 1.20 1.25 1.30 1.35
Ratio of experimental frequency to calculated frequency